On 09/05/17 22:39, Steven Hanley via linux wrote:
> All
>
> Seamus offered this talk up for May and it sounds like it will be
fun and
> interesting so come and learn/discuss/etc.
>
> See below, 18:00 at Wig and Pen for BeerSig
> 19:00 at CSIT Building ANU - N101 for CLUG.
>
> Canberra Linux Users Group Meeting - 25th May 2017
> =================================================
>
> Date: 25th May 2017 (Fourth Thursday of the
month)
>
> =================================================
>
> Time: 18:00 - 18:55
>
> Abstract: It's BeerSIG time!
> 'What's BeerSIG?' I hear you ask!
BeerSIG is a social
> gathering, and an opportunity to get
together with
> like minded people and share a social
pint
> or two before the meeting.
>
> Location: Wig and Pen, Llewellyn Hall, Canberra School of
Music
> Look for the table with a stuffed toy
penguin
>
> =================================================
>
> Time: 19:00 - 21:00 (or when it finishes)
>
> Title:
>
> * An animated explanation of how the packet loss and latency
displayed

Re: Um... Is there CLUG tonight?

On 26/05/17 07:28, Mike Carden via linux wrote:

> On Fri, May 26, 2017 at 6:29 AM, George at Clug via linux <
> [hidden email]> wrote:
>
>> Well I missed another meeting.
>>
>> The days, weeks and months are travelling way too fast for me.
>>
>> Was it a good night, what was discussed ?
>>
>
> The bit I saw before I had to go and be a taxi was very good. Seamus was
> digging into traceroute and what it does and doesn't tell you about what an
> IP network is doing.
>
> I hope that the resources from his talk are online somewhere because I
> really wish I hadn't missed the rest.
>

+1 - Seamus did a great job and his animated diagrams of how traceroute
output can represent many different scenarios were excellent.

Alas, his "slides" (9000 images, apparently, and around 8GB) are not
yet ready to be put on the web.

A huge thanks to him for travelling all the way from Sydney just to
present this talk for us.

One interesting point, early on in his presentation, was around 7
very different traceroute outputs for the same (hypothetical)
destination that were all good and one that may have been good or
bad - this brought home his point quite well, I thought.

He mentioned to me, after dinner, that DigitalOcean and Linode both
have tutorials on traceroute that are worth a read, although the one
I found on DigitalOcean seemed to be making some opposite (and naive)
points to Seamus's talk. For example, Seamus talked down the use of
mtr (My TraceRoute), but the DigitalOcean tutorial talks it up, etc.

Re: Um... Is there CLUG tonight?

>
> Afterwards I ran tracepath against some Aussie Web sites. So I was
> surprised to discover that Socialist Alliance and Green Left Weekly--had
> their sites located in Tokyo!
>
>
Bryan, what command did you execute that led to that conclusion?

Re: Um... Is there CLUG tonight?

Hi Mike:

> Afterwards I ran tracepath against some Aussie Web sites. So I was
> surprised to discover that Socialist Alliance and Green Left
> Weekly--had their sites located in Tokyo!
>
>
>
> Bryan, what command did you execute that led to that conclusion?

First, the following.
{
tracepath socialist-alliance.org
}

Which after some Canberra and Sydney servers, produced this. I would
have looked up say "hkix.net" directly in Firefox, showing that was a
Hong Kong service. Though I wasn't able to connect with "pccwbtn.net"
similarly, as with "139.162.64.17".

Re: Um... Is there CLUG tonight?

Latency that the only present for some of the intermediary routers. Multiple potential causes, including..
Router control plane delays
1 or more long/slow return paths from 1 or more intermediary routers

10 ms
20 ms
30 ms
200 ms
210 ms
220 ms
230 ms
240 ms
90 ms

Packet loss that the only present for some of the intermediary routers. Multiple potential causes, including..
Router control plane no generating the ICMP Time exceeded messages
1 or more return paths from 1 or more intermediary routers causing packet loss

10 ms
20 ms
30 ms
*
*
*
*
80 ms
90 ms

In-line latency that continues all the way to the remote destination host

> On Fri, May 26, 2017 at 6:29 AM, George at Clug via linux <
> [hidden email]> wrote:
>
>> Well I missed another meeting.
>>
>> The days, weeks and months are travelling way too fast for me.
>>
>> Was it a good night, what was discussed ?
>>
>
> The bit I saw before I had to go and be a taxi was very good. Seamus was
> digging into traceroute and what it does and doesn't tell you about what an
> IP network is doing.
>
> I hope that the resources from his talk are online somewhere because I
> really wish I hadn't missed the rest.
>

+1 - Seamus did a great job and his animated diagrams of how traceroute
output can represent many different scenarios were excellent.

Alas, his "slides" (9000 images, apparently, and around 8GB) are not
yet ready to be put on the web.

A huge thanks to him for travelling all the way from Sydney just to
present this talk for us.

One interesting point, early on in his presentation, was around 7
very different traceroute outputs for the same (hypothetical)
destination that were all good and one that may have been good or
bad - this brought home his point quite well, I thought.

He mentioned to me, after dinner, that DigitalOcean and Linode both
have tutorials on traceroute that are worth a read, although the one
I found on DigitalOcean seemed to be making some opposite (and naive)
points to Seamus's talk. For example, Seamus talked down the use of
mtr (My TraceRoute), but the DigitalOcean tutorial talks it up, etc.

Re: Um... Is there CLUG tonight?

Bryan
If you are interested in using traceroute for its intended purposeof tracing out the route to a remote node.
Then I suggest that you have a look at some of the talks by
Richard A Steenbergen. He goes into quite a bit of detailon how to use the dns names of routers to determine theirlocation and their function.

> Afterwards I ran tracepath against some Aussie Web sites. So I was
> surprised to discover that Socialist Alliance and Green Left
> Weekly--had their sites located in Tokyo!
>
>
>
> Bryan, what command did you execute that led to that conclusion?

First, the following.
{
tracepath socialist-alliance.org
}

Which after some Canberra and Sydney servers, produced this. I would
have looked up say "hkix.net" directly in Firefox, showing that was a
Hong Kong service. Though I wasn't able to connect with "pccwbtn.net"
similarly, as with "139.162.64.17".

Re: Um... Is there CLUG tonight?

* It enables people to easily and continually send multiple packets to the
control planes of other peoples routers.* It gives people an even more of a false sense (than traceroute) that they have a full picture of what is going on.* People often misinterpret the packet loss column.
CheersSeamus

> On Fri, May 26, 2017 at 6:29 AM, George at Clug via linux <
> [hidden email]> wrote:
>
>> Well I missed another meeting.
>>
>> The days, weeks and months are travelling way too fast for me.
>>
>> Was it a good night, what was discussed ?
>>
>
> The bit I saw before I had to go and be a taxi was very good. Seamus was
> digging into traceroute and what it does and doesn't tell you about what an
> IP network is doing.
>
> I hope that the resources from his talk are online somewhere because I
> really wish I hadn't missed the rest.
>

+1 - Seamus did a great job and his animated diagrams of how traceroute
output can represent many different scenarios were excellent.

Alas, his "slides" (9000 images, apparently, and around 8GB) are not
yet ready to be put on the web.

A huge thanks to him for travelling all the way from Sydney just to
present this talk for us.

One interesting point, early on in his presentation, was around 7
very different traceroute outputs for the same (hypothetical)
destination that were all good and one that may have been good or
bad - this brought home his point quite well, I thought.

He mentioned to me, after dinner, that DigitalOcean and Linode both
have tutorials on traceroute that are worth a read, although the one
I found on DigitalOcean seemed to be making some opposite (and naive)
points to Seamus's talk. For example, Seamus talked down the use of
mtr (My TraceRoute), but the DigitalOcean tutorial talks it up, etc.